LAS VEGAS >> The IRS says boxer Floyd Mayweather Jr. still owes $22.2 million in taxes from 2015, the year he earned his biggest payday with a blockbuster fight against Manny Pacquiao.

A notice of a federal tax lien filed against the undefeated fighter nicknamed “Money” shows the balance as unpaid as of March 6. The document was filed with county officials in Las Vegas in April.

Mayweather’s tax troubles come as he gets ready to come out of retirement to fight against Irish MMA star Conor McGregor in August.

The lien for 2015 is just the latest in a series of tax liens filed by the IRS against Mayweather over the past decade.

Mayweather’s tax attorney did not immediately return a request seeking comment on Tuesday.

Mayweather himself was set to appear at a news conference in Los Angeles to promote the fight, the first of four this week.

He said in a Facebook post that he paid the IRS $26 million in 2015, and that he’s sure he would have been notified much sooner had there been any “real discrepancies.”

Mayweather said: “My empire is rock solid and intact.”

Fight site set

Floyd Mayweather’s boxing match against Conor McGregor will be held at T-Mobile Arena in Las Vegas after promoters reached an agreement with Ice Cube to move the championship game of his Big3 basketball league.

The final game of the 3-on-3 season of former NBA players will now be held at the MGM Grand Garden Arena on Aug. 26, with a 4:30 p.m. Eastern start. The bout is at night.

The Big3 said Tuesday it reached a financial and promotional deal with MGM Resorts, Mayweather Promotions and UFC. Terms weren’t disclosed, with the rapper-actor and Big3 co-founder Jeff Kwatinetz simply calling it a “generous offer that we could not refuse.”

“We are happy we could work together to create an opportunity for our fans to experience both events, making Aug. 26 the most exciting day in sports and entertainment Las Vegas has ever seen,” they said in a statement.

Mayweather will be returning from retirement to face the Irish mixed martial arts star and UFC President Dana White had said the match would be held at T-Mobile, the largest venue in Las Vegas. But the arena had continued to list the basketball game on its schedule of events.

Opened in 2016, T-Mobile Arena lists a capacity of 20,000 for boxing, about 3,000 more seats than the MGM Grand Garden Arena.